feat(cli): synth prints validation report

[kaizencc]

Right now, cdk synth relies on the legacy pretty-printed report written by the validation plugin logic in aws/aws-cdk. This PR aims to replace that with the modern report that cdk validate uses. A subsequent PR will be made to remove the legacy report stlye from aws/aws-cdk.

The new model is:

• The validation plugin system that runs during synthesis creates a validation-report.json artifact detailing all validation mechanisms in one place. It does not handle printing anymore.
• the CDK CLI handles writing to console. This means it takes the validation-report.json and both cdk synth and cdk validate writes the same style report to the console.

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.73%. Comparing base (425ccb0) to head (6ff3a2d).

Additional details and impacted files

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##             main    #1633   +/-   ##
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  Coverage   88.73%   88.73%           
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  Files          77       77           
  Lines       11359    11359           
  Branches     1584     1584           
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  Hits        10079    10079           
  Misses       1250     1250           
  Partials       30       30           

Flag	Coverage Δ
suite.unit	88.73% <ø> (ø)

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